1. Field of the Invention
The present invention relates to a range interlock for a compound range type mechanical transmission which will inhibit shifting of the main transmission section from neutral during a range shift transient, and in particular, to a resilient range interlock for a compound transmission which will resiliently inhibit, but not prohibit, shifting of a compound transmission from neutral during a range shift transient.
2. Description of the Prior Art:
Compound transmission systems comprising manually shifted multi-speed main transmission sections connected in series with one or more multi-speed auxiliary drivetrain sections, usually of the range, splitter or combined range/splitter type are well known in the prior art. The auxiliary sections are usually input and/or output auxiliary transmission sections but may also be multi-speed drive axles, transfer cases or the like. Examples of such compound systems may be seen by reference to U.S. Pat. Nos. 4,754,665; 3,648,546; 3,429,202; 4,455,883; 4,561,325; 4,663,725, 3, 799,002; 4,455,883 and 4,527,446, the disclosures of which are hereby incorporated by reference. These transmissions, are well received and widely utilized in manually shifted heavy duty vehicles.
As is known, in the prior art controls for range type compound transmissions, an interlock is required to retain the main transmission section in neutral during a range auxiliary section shift transient.
These prior art controls are not totally satisfactory as an interlock to inhibit, but not prohibit, shifting of the main transmission section until the selected auxiliary range ratio is fully engaged was not provided.